he was cornered in a boat in a backyard. 19-year-old dzhokhar tsarnaev. his brother tamerlon was shot and killed earlier. >> reporter: their mission was take him down and they did. people recorded the gunfire from their windows. for a second night the search for the suspect focused on a 20 block area in massachusetts. this time authorities exchanged gunfire with suspect number two, dzhokhar tsarnaev. someone snapped this photo right after the take down. authorities say the 19-year-old suspect had been shot but was arrive. >> we're exhausted folks but we have our man. >> he walked outside, he saw blood on the boat of a backyard. he then opened the tarp and saw a man covered with blood. >> it's about accountability, i can't say how happy i am. how pleased i am that the second subject was taken alive. >>> tonight's arrest made a 24 hour man hunt to an end. it all started yesterday when the fbi released those photos of the suspects. then sean collier was killed in his cruiser. moments later the two stole a mercedes suv. suspect number one, the man in the blac